1. Field of the Invention
This invention relates to a polyimidesiloxane film of low heat-conductivity. More particularly, it relates to a polyimidesiloxane film of low heat-conductivity having a high hardness, a high heat-resistance and a superior adherence onto its substrate.
2. Description of the Related Art
Polyimide resins have a superior heat resistance and also superior mechanical characteristics and electric characteristics; hence they have been broadly used as protecting materials, insulating materials or adhesives in the fields of electronic equipments, films and structural materials. However, depending upon use applications, polyimides for enhancing heat insulating properties have often been desired. For such a use application, there have been used polyimides having a part of diamine component as the raw material, replaced by dimethylsiloxane oligomer of the following formula (9) having 3-aminopropyl group at both the ends thereof: ##STR2## wherein m represents 1 to 100
(see for example, Japanese patent application laid-open Nos. Sho 57-143328, Sho 58-7473, Sho 58-13631, etc.).
However, these polyimide resins have a low heat-conductivity, but as their surface hardness lowers, the heat resistance lowers down to about 300.degree. C.; hence they have a drawback that their use applications are restricted.